Tackling the future challenges of Organic Animal Husbandry - vTI

Abstract
RAHMANN G & GODINHO D (Ed.) (2012): Tackling the Future Challenges of Organic Animal Husbandry.
Proceedings of the 2 nd OAHC, Hamburg/Trenthorst, Germany, Sep 12-14, 2012
Run management for organic layers
VERONIKA MAURER*, ZIVILE AMSLER-KEPALAITE, FELIX HECKENDORN,
MARTIN KOLLER, ERIKA PERLER, ESTHER ZELTNER
Research Institute of Organic Agriculture (FiBL),
5070 Frick, Switzerland, *veronika.maurer@fibl.org
Layer runs are often bare and loaded with nutrients and with infectious stages of helminths. Various
management strategies are recommended in order to better distribute the hens in the run,
thereby preventing local accumulation of droppings and related problems. However, little is known
about the impact of those strategies.
A series of on farm experiments has been performed in order to test the effects of flock size and of
artificial structures on the dispersal of the hens in the run. Further studies evaluated the effects of
mowing and run size as well as rotational use of runs on turf quality, nutrient load in the soil and
on the infection of the hens with internal parasites.
As a summary, introducing structures or applying a rotational management scheme improves run
use and facilitates mowing, thus improving turf quality in the run in front of the henhouse. However,
the expected reduction of helminth infections and nutrient accumulation has not been observed.
Key words: laying hen; outdoor run; internal parasites; nutrient accumulation
Introduction
Organic layer farms have become more numerous in recent years. In these systems, hens benefit
from access to a free range area. However, management of a hen run is a difficult task, since hens
tend to remain near the henhouse, where droppings accumulate. Consequently, this area is often
bare and loaded with nutrients (particularly phosphorus and nitrogen) and with infectious stages of
the two main helminth parasite species of poultry (Ascaridia galli and Heterakis gallinarum). Various
management strategies are recommended in order to better distribute the hens in the run, thereby
preventing accumulation of nutrients in the soil as well as parasitic infections of hens. This paper
summarises results of several on farm experiments with different run management regimes carried
out by the Research Institute of Organic Agriculture in the past years.
Material and Methods
A series of on farm experiments has been performed in order to test the effects of flock size and of
artificial structures on the dispersal of the hens in the run. A first study examined possible effects of
a roofed sandbath on numbers of hens using the run and their distribution in the run on an organic
poultry farm with 8 flocks of approximately 500 animals. Each flock was observed with and without
roofed sandbath during three days by means of eight scan samples per flock and day. Impacts of
weather conditions could be eliminated because always half of flocks were with and half without
structure at the same time. See Zeltner & Hirt (2003) for further details.
A further study focused on the effects of mowing and run size on turf quality and on infection of the
hens with internal parasites. This experiment conducted at four sites in Switzerland investigated the
transmission and infectivity of A. galli and H. gallinarum on outdoor runs with two different stocking
rates. Additionally, the influence of a simple management practice (mowing of the run) on helminth
transmission was studied. Three run types were created on each site: runs C served as control
(stocking rate 10 m 2 /hen, no management), runs B corresponded to runs C but were managed (10
m 2 /hen, management). In runs A stocking rates were doubled compared to control runs (5 m 2 /hen,
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